苦胺酸偶氮变色酸光度法测定硝酸镍中痕量钴

SPECTROPHOTOMETRIC DETERMINATION OF TRACE COBALT IN NICKLE NITRATE WITH PICRAMAZOCHROM

研究了苦胺酸偶氮变色酸与钴显色反应的条件。在氨性条件下，试剂与钴发生显色反应，最大吸收波长为６４５ｎｍ，摩尔吸光系数为２．６５×１０＾４Ｌ／（ｍｏｌ·ｃｍ），钥含量在０￣２０μｇ／２５ｍＬ内符合比尔定律。在以大量基 元素打底的民政部下，不需另加任何掩蔽剂，可直接测定硝酸镍中的痕量钴。

The color reaction of Co with the reagent picramazochrom has been studied.In ammoniated medium,the reagent forms with Co a stable complex exhibiting a maximum absorption at 645 nm.The.molor absorptivity of the complex is 2.56×104 L/(mol·cm).Beer' s law is obeyed for 0 ~ 20μg/25 mL.It can be used for the determination of trace amount of Co in nickle nitrate without adding any masking agent,the presence of large amount of matrix elements is tolerated.